Hull of ships



Oct. '21, 1930. E. G. E. HOGNER 1,779,041

HULL oF SHIPS Filed Jan. 15, 1929 1 sheets-sheet 1 /NveNTole oct. 21, 1930. E. e. E" HOGNER 1,779,041

HULL OF SHIPS Filed Jan. l5, 1929 4 Sheets-Sheet 2 Oct. 21, 1930. E. G. E. 'HOGNER 1,779,041

y HULL 0F SHIPS Filed Jan. 15, 1929 4 sheets-sheet '3 L WL 'l l 175g!! LWL Oct. 21, 1930. E. G. E. HOGNER 1,779,041

HULL OF SHIPS Filed Jan. 15, 1929 4 Sheets-SheetI 4 fig@ LWL.

LWL.

Patented Oct. 21,` 1930r f dliaoii` Y. EINAReI-rsrer EvALn noennn, orstrooigjiioning,srvnizpnlvf L 1 Y HULL or' siiirs Application 'sieri January l1"5, 'ieaal'serirai No. 332,577, and ia swedenv Januaryge; '1928.'A r

This Y invention relates to limprov einents 'in propeller-driveng ships having hulls of y'ordinaryshape, and theprirnaryrohject of the in vention is to bring about 'in such ships anni# e i1-orma distribution ofther Wake* aro-und` the propeller airis.k y 5.-' fff Y l To this end, the run 'of the ship isprovided e With at least one 'submerged bulge-'shaped projection surrounding they propeller "axis, n

and an afterfhody extending Vlengthwise 'loe'- yond said projection; and further .With a bending in .between the projection and the after-body; saidbending iny separating said j Vpartis to such anxent'entas to leave the projec;

f tionentirely free for the greaterufpartoffits length, Y Y yThe said projections mayas to their shape f coincide substantially vvith'tvhez'shapev ofone or'more loodiesjo revolution may he y flattened orvmo'dified f in other respectsY or their" forniinay beftotally different from.

forni of revolution. Moreover, Where a'vpluf rality of'loulh-shap'ed pro-jectionsa're provided, the bottom of the ship'between` the said 25 ro'e'ctions runs in auniforml risindV curve or line from the ykeel and'upwardly toward the level Water line, in order to facilitate a soft streamingA off of the Water rointheliull of, thefship,and also by adaptation of jthe curves. or, lines between .thelprojection's vwith respect to each other in 'relationV tothe shapek and Vsize of the;fsaidjrestrictions or'l channel-shaped formations. bring ,about lsuitable circulation 'of the Water aro-und lthel said bulge-shaped projections. For the :saine purpose it is. suitalolev to provide-helically j' arranged guide surfaces,k ridgesjgwings yor blades, on. the said bulge-shaped projection in tronto-f thehindinostend of the said parts With a propeller provided thereat if desired.V

Thus a twofold advantage obtained; in the irstplacethe guide surfaces will be situated in a stream Which is not directly vactuatedbyv the propeller, so'that'fthe rictional vlosses will he smaller, and -,s`econdly, the guide surv` im or projections, preferablyv atl some distancel Some embodiments fof @the` inventionl 'areglif disclosed in theYaccompanyingdrawings.

llligs.Y lillustratethe after-body ofvalship"v 'y :f I with voneprepeller, While Figures 4-6 show' the afterbodyoi ajship providedeWithtWo propellers; ln'the draWings,Figs."'-l ande represent' elevations "with'thelongitudinal fff' sections l and -Hwhile Figs `and 5..shoW 1 e Waters-lines lei-3 "and they load Water line e0 formed at l@ Oilffh lnesofa bulge-shaped projectionf-here a cone with the apex 'directy edjaftvardlythe;axis of which.A coincides' .f Y Witht-hetpropeller''axes` and atthje/apeX/.'t' '7'0 w'vhich'the' propeller is provided. Ahead the mantle sur-face ofthe e'onilcalpart passes over by degrees into the ordinary: forni of a ship. In Figs. 1 and 3,v another' shape Withf'a curvedl j generatrix is also indicated'by dottedlines b. 7:5

n-V'Fig. 4, line .d'irepresentsl the shape' With Which,thefhottom of the ship betweenthe :two

vconical/parts a' is extended frornthelreel and upwardly toward" the'loadl. WaterlineAt f j 1 in Fi'gfsg 152,4 and'fis'shown'the'channelL 80 Shaped @matrona-the Surface of fheiiunef 5 the 'ship,t said formation extending here'from i theA aeighborhod of Y the bugie to' the upper i sideof-the''conical parts a'.f*-In Figs.'1- 3,'a helically arranged guide apparatusfin 'the v 85 form of a ridge isin'dicatedat g3 andiny Figs. 4-6. Va guide apparatus 'in the form'of a helicallyV arranged*loladeeisindicated at h, said .i

guide apparatus.beingplacedat'some distanceV lfrontfoffthe propeller: Eorfthe sakef off 90 -siinplicit-yonlyone guide elementis shown in vboth cases, it being obvious that they prefer aloly are ltobe distributed uniformly aboutl the l propeller axis. lilachkind ofguide apparatus Y maj/evidently be usedinshipsrhavingl one 95.;

of propellersl.

propeller as Well as in ships having a plurality The mode af permita vfof [the apparatus 'd should; beclean from .theabev description; Y 'By reason of thete'rminatio'n the runof the mf@ Cai ship, which termination is one of rotational i symmetry around the propeller axes, vthe wake current willbe distributed about the propeller axes with bettersymmetry of revolution than wit-h the ordinary shape of the run of a ship.

It is possible however, that the Wake having the best symmetry of revolution'will be real-l ized with another bulge formwhich in every case is to'be designed, with-respect to existing vconditions. The channel formed between'the bottoni ci of thefship and theconical'parts a` (see Z in Fig. 4) in the embodiment provided withv two propellers forms a favourable vpath for the watercoming from theA lower-.side of the bottom, andv the upwardly directed streaming heremwill bring` about circulationi' about the conical parts.V --By adapting the said channel andthe channel-shapedformations f f to'each other the circulation maybeniodifiedq -20 a greaterjextent,by means ofthe .guide` apparatus, as described hereinbefore.

tosome extent,;which also-bee cted, to

Fig. 7- illustrates are afar-boden a ship havingraf: body of revolution similar `toxthat Vdead water.

one shown in Figs. '1 'and"2, saidrlatterbody -being here Vprovided withV ailreel-shap'ed projection u at its under side for `the purposeof obtaining a more favourablestreaming of the In the form ofembodiment, shown Sthe projectionahas in section the shapejof a pear, andaccordingto "Fiz9 the said projec-V i tionis egg-shapedand, besides, obtains. ran.

unsymmetrical position relatively .to the hull of the ship,v the bulb-shaped projectionbeing helically twisted, :as shown, in order -to `bring the water-to circulate around the axis.

Figs. 10 andll'illustrate arrangementsofr' the projection@,similar to those shown in F1gs..8 and 9, respectively, but applied toa ship having two Propellers, the'projection shown in. Fig. 11 being somewhat twisted.` j

Figs. 12 and 13 illustrate anV embodimentV Similar to einem Shown in Figfmhe keelshapedl projection'u being, however,`:-in this caseprovidedwith a bulb u giving the stream-v ingcfjthe dead water suitable distribution.

i j rlherbulb fv extends aftwardly andfformsza' j j o the propeller;

sdupportforthe stern post pcarryingthe rud-v j lL'illustrates similararrangement applied toa twin-screwship. 'i

.Y Figii 15 illustrates the rfore-body sorteren; trance of aship vhaving-a bendingin atffw,

similar to the bending in at thev after-bodies part of the hull properrand supportingthe t propellershaft.:

shows the invention ap-V ried into eiectv other -Vways, agreeing inl v principle, however, with the appended claims. rlhe bulgeformed` vprojections may be given different shapes, the same being generated,

for instance by generatrices Vof different shape o r said projections may be vgiven shapes built up on the lines Vof..modiied bodies of? 1 revolution 'por A from forms ldiiferingY totally of the Vtrue Vform of revolL'itionL-Their numberfmayfalso be greater than two, for instance Ain the'caseof a greater numberof propellers.

It' is conceivablethat the formation Vofan is used evenQif-n'o propellers Yare provided.

Obviously, thel'invention also'rcomprises' a l `construction where the overhungk after-body or stern la issupported further aftwardthan indicated"inthedrawing, by the part a by means of special supports, or lbythe parts a beingto some-extent built together with Ythe part la. ,ln-'ships' provided with a plurality of propellers similar :supporting or similar building together'may also beinade use of.

after-body in accordance withthe-invention In these cases,"fhowever, the free part of the bulgelshaped projection must extend far enough to cause aV streaming .v having Vrotational symmetry atthe endof the saidfprojec#` tion. The guide apparatus may be given different shapes anddimensions, the ridges `beingfforV example, made fwider or'longer than indicated 'inthe drawing, andtheirposition H being altered withinV the` scope ofthev in.- v yention. 'Otherwisefthe construction of the vafter-body is'ar'bitrary; for' example, the curve may extend horizontally immediately Vunderneath vthe level water line,- said. curve indicating a horizontal fiat bottomv in the aft*` `most portion ofthe after-body. Rudders of any suitable construction may evidently be provided, with or without a lower support of constructional members projecting from the bulge-shaped proj ectifonsor Afrom other parts of the af ter-body.jf

vVhat Iclaim isz--y i l. In propeller-,drivenships having a hull of ordinary shape, the provision on the run of the `shipof at least one submerged bulgeshaped projection .surrounding Athe propeller axis, anl after-body extending lengthwise beyond saidbulge-shaped projection,` and a bending vin betweensaidprojection and said v lafter-body, said bending iii-separating saidv parts oflsuch an extentast'o leave the projec-` tion entirely freeV to the greater. part of its .length and said projection having such a shape as lto bring 'about v a` uniform 'distributionof the wake around the propeller axis.

' '2. An arrangement accordingV to :claim 1,- characterized byV the submerged bulge-V shapedl proj ectionfhaving a keel-shapedv appendix at itslowerside. f Y ln testimony whereof I aflix mysignature.

EINARGUSTAF,EVALD HOGNER. 

